The first group of experiments will be performed to examine the organization of cerebellar afferent pathways. Emphasis will be placed on experiments designed to test the hypothesis that the spatial features of somatotopic projections are not sufficient to account for the information processing occurring in the cerebellum. Studies of the temporal characteristics of the responses recorded in cerebellar afferent pathways will be done to support the contention that this parameter is very significant to the integration occurring in the cerebellar cortex. Other studies will examine the role of extrapyramidal projections in mediating the action of the deep cerebellar nuclei on spinal reflexes and motoneurons. In a final series of experiments a chronic behavioral paradigm will be used to study the role of certain central nuclei in the learning of a specific movement.